Radiator shutter construction



March 23, 1943.l E. A. BLUMENTHAI. 2,314,476

A RADIATOR SHUTTER CONSTRUCTION Filed Sept. 19, 1940 3 Sheets-Sheet 1 lif 79 I? I -l` March 23, 1943. "E, A. BLUMENT'HAL 2,314,476

fADIAToR sHUTTER CONSTRUCTION Filed Sept. 19, 1940 5 Sheets-Sheet 2March 23, 1943. vE.` A. BLUMENTHAL RADIATOR SHUTTER CONSTRUCTION sSheets-'sheet vs Filed Sept. 19, 1940 (S/Mnwm fyw Patented Mar. 23, 1943UNITED STATES PATENT OFFICE 1) Claims.

This invention relates to an improved type of shutter device as appliedto air cooled radiators for motor vehicles and more particularly it isdirected to a type of construction that is made up of blades, eachhaving two or more sections. Although the shutterherein disclosed isreferred to as being particularly applicable to radiators of motorvehicles, it will be understood that the principle of construction maybe used generally wherever shutters are to be used.

In United States Letters PatentJ No. 2,174,358, granted September 26,1939, I have disclosed and claimed an improved type of sectional shutterdevice adapted for use with radiators of internal combustion engines andparticularly for use in connection with the false front type ofautomobile radiator and capable of being applied to all sizes ofradiators of this type without re quiring special parts or fittings tocompensate for size variations. viding blades of different lengths, eachblade is made sectional, the parts being adjustable so that differentlengths may be obtained. I found, however, that overlapping edges couldnot be'made to engage tightly When the blades were thus made sectionaland that for a portion of the length of each blade a space equal to thethickness of la blade section would be left between adjacent bladesalong their adjoining edges. These spaces prevented the shutterconstruction from being air tight when closed and allowed air to flowtherethrough in such volumes as to affect the eiciency of the device incontrolling the a1r ow to the radiator during cold weather.

An object of the invention is to provide an improved shutterconstruction of the sectional blade type having means for effecting atight closure for the area it protects or spans, and to provide by saidmeans edges of adjoining blades that overlap in closed position andeliminate thereby openings between the blades at said edges as theresult of said blades being of the sectional type.

The invention is directed primarily to an improved blade constructionand an arrangement of the blades with respect to each other whereby,although each blade may be made of a number of sections, the edges ofadjoining blades willengage and form a very effective seal, therebyeliminating openings between blades that allow the air to flowtherethrough.

A further object of the invention resides in providing the aforesaidimprovement in the type of shutter construction disclosed in my priorpatent. To this end, the invention has, as a` purpose, the embodiment ofthis improvement in In order to eliminate pro- Sil a design of shutterof standard sections or parts that can be readily assembled, orassembled and mounted, upon radiators of different heights and differentwidths, each part or blade preferably being extensible to adapt itselfto different Widths and sizes so as to permit ready assembly uponradiator fronts of different heights. Before the adoption of the falsefront or grille of the present day automobile, it was necessary to carryin stock a great number of shutter parts to meet all the requirements ordemands made necessary by the different sizes, shapes and designs ofcars adopted by different car manufacturers. Dealers were obliged tocarry a large stock of shutters due to the number of sizes required andwere obliged to suffer substantial inventory losses each year when newmodels made their appearance upon the market. The confusion and addedexpense of carrying a stock on hand of all sizes of shutters and theexpense of dies and tools to manufacture the same greatly increased notonly the cost of manufacture but also the cost of distribution. Thepresent invention is designed to be adapted to a shutter constructioncapable of fitting radiators of different sizes Without requiringadditional parts or fittings and without requiring the making of morethan one design of blade section that may be used to complete theassembly of the entire shutter. Hence, it will be necessary to carryonly a single type of blade section in stock and to provide but a singleset of tools in the manufacture thereof.

It is commonly known that road shocks and vibrations to which motorvehicles are constantly subjected cause parts to loosen and that anyvibration or noise as the result of such loosening or tolerances ofmanufacture, as Well as of wear, is extremely objectionable and is to beavoided. In the case of shutter mechanisms, the blades often rattle whenin closed position due to such vibration.

It is, therefore, a still further object of the invention to providemeans for preventing the blades of a shutter mechanism from rattlingwhen in closed position. It is found that this means may simply beincorporated in the blade construction by warping the blades, either inthe formation thereof or in the closing thereof, so that these bladeswill bind when held in closed position, and therefore not free torattle.

Other objects and advantages of the invention will be apparent from theAfollowing description taken in connection with the accompanyingdrawings, which form apart hereof.

In the drawings:

Figure 1 is a front elevation of a shutter assembly embodying thepresent invention;

Fig. 2 is an enlarged detail view looking downwardly upon the structureto show the manner in which the side frame members carry the blade unitsand their ttings, only the two end blade units being shown and all otherparts of the structure being omitted;

Fig. 3 is also an enlarged detail View of a por- -tion of the shutterassembly mounted in front of a radiator core and illustrating thermallycontrolled means that may be employed to effect opening and closingadjustments of the blades;

Fig. 4 is a horizontal sectional View through three of the blades inclosed position, this section being taken through the upper bladesections and looking downwardly so as'to View the upper ends of theblower blade sections in elevation, to illustrate the overlapping ofadjacent blades without leaving a metal thickness separation betweenblades caused by overlapping of extensible blades;

Fig. 5 is a similar view but illustrating the l blades in open position;

Fig. 6 is a view similar to Fig. 4 but of the prior art extensibleblades to illustrate how superposed blade sections of the prior artcaused separation openings of a metal thickness between the blades whenclosed;

Fig. 7 is a perspective view of a single extensible blade embodying theinvention;

Fig. 8 is a side view thereof but with the sections separated;

Fig. 9 is a perspective view of an extensible blade formed of more thantwo sections;

Fig. 10 is a side view of the same;

Fig. 11 is a perspective View of a plurality of extensible blades toillustrate that the present invention is capable of embodiment of anytype of shutter mechanism and is not limited to a radiator shutterconstruction for use in connection with internal combustion engines;

Fig. 12 is an enlarged sectional View taken on line |2-I2 of Fig. 11;

Figs. 13 to 23, inclusive, are detail sectional views illustratingvarious forms of overlapping engagement between adjoining extensibletypes of blades that embody the invention;

Figs. 24 is a cross-sectional View through an extensible blade havingthe blade sections thereof formed with the same radii but, due to thethickness of the metal, do not nest one in the other when placedtogether;

Fig. 25 illustrates the manner in which these blade sections will springor warp when drawn together into surface engagement whereby they 4willbind against one another when secured together to prevent rattling;

Fig. 26 is a perspective view illustrating two @adjoining extensibleblades being moved together in closed .position to show how a slightwarping at one end of the blades, preferably the lower end, will causesaid adjoining blades to bind against each other and thereby be heldsun'iciently tight together to make for a better seal and to .preventrattles;

Fig. 27 is a perspective view of a blade section illustrating a taperedoverlapping iiange along one of its longitudinal edges;

Fig. 28 is a detail perspective view of adjoining extensible bladesformed with the tapered ange shown in Fig. 27 and with a trough-likecooperating flange in which the tapered flange is received as thesectional blades are moved to closed position so as to slightly distortthe Iblades and cause them .bindingly to engage each other, therebyeliminating any rattling or noises between adjacent blades due tovibration; and

Fig. 29 is a sectional detail view through a portion of a blade toillustrate the dried iinishing coating on the blade Aforming apuncturable webbing closing the apertures therein adapted to form partof the Ifastening means holding the blade sections in extensiblerelation.

The improvement herein disclosed is directed to a shutter constructionhaving a plurality of individually pivoted blades adapted to swing toopen or closed positions. Each blade is preferably extensible in orderto provide an adjustment that permits the shutter construction to beadapted to areas of different sizes and comprises superposed bladesections adjustably movable lengthwise of each other. It will beunderstood that the invention is not to be limited to a shutterconstruction for radiators of internal combustion engines, because thenovel feature of forming a shutter construction of the aforesaid typethat eliminates a metal thickness separation between adjoining blades atthe overlapping edges may `be advantageously used wherever a closure ofthe shutter type may be employ-ed.

As shown in the form illustrated in Figs. 1 to 5 and 7 to 12, inclusive,each shutter blade comprises at least two blade sections, the upperblade section 2 and the lower blade section 3, these being arranged insuperposed relation with suitable fastening means 4 for holding the samein an extended relation. Fastening means 4 may comprise lips carried byone or both .blade sections .which are adapted to enter perforations 4in the other blade section and be bent over in order to hold these bladesections in one of a plurality of adjustable positions.

The outer ends of -blade sections 2 and 3 are provided with end flangesShaving openings 6 punched therein so that heads l of studs 8 may beforced through openings 6 and locked therein, as illustrated in Figs. 4and 5. Studs 8 are carried upon a plurality of ttings 9 disposed atopposite ends of blade sections 2 and 3. In so far as the presentinvention is concerned, it is immaterial how studs 8 are carried atopposite ends of lblade sections 2 and 3, the novelty herein disclosedbeing directed to the construction of blade sections 2 and 3 and theiroverlapping relation to provid-e a tight closure that prevents leakageof air when the vblades are in closed position.

As previously mentioned,however, the present shutter construction may beuniquely adapted to the sectional shutter assembly disclosed in my priorpatent. If thus employed in a sectional shutter assembly, one specificform of end ttings 9 may bethat of sleeves that t over and upon rods i0.Rods H) are suitably supported at their ends, say, in frame members I lvhaving slotted sides I2 adapted to receive suitable bolts I3 or likefastening elements adapted to pass through openings between the verticalwater pipes of the core of a radiator broadly shown at I4. Frame membersIl may be suitably designed so as not to interfere with the pivotalmovement of the end blades to their open and closed positions. It is notessential that these end frames Il be employed along the vertical sidesof the shutter assembly. If the blades are placed horizontally, endframes may or may not be employed along the top and bottom sides of theassembly, and if omitted, mounting brackets may be carried by one ormore of the end ttings and may secure the shutter assembly to theradiator front, as shown in my prior patent.

Employing .end fittings 9 and rods l0 allows the blades to be arrangedin sectional units. The sectional units may carry any number vof bladesso that they will readily complete an assembly to t various sizedopenings. As illustrated in Fig. 1, the first sectional unit to the lefthas two blades, while the next several sections have three blades. Thesectional unit at the right has onelblade only. In assembling thesectional units, the attendant will be able to remove from stock on handthe number necessary to complete the closure, using one, two or threesectional blade units in the assembly, when necessary, to secure theproper number of blades.

Manual -or automatic operation of the shutter blades to effect openingand closing adjustments may be accomplished in any desirable way, therebeing shown, however, a thermostat I5 adapted to be mounted upon theradiator core by means of bolts I6, or the like, and a flexibleconnection I`| leading therefrom to a bracket I6 that may be carriedupon fittings 9 of one of the sectional blade units. Housing I9 offlexible connection I1 may be suitably anchored in bracket I8. Aflexable member or wire 2| passing through housing I9 may be attached toa pin 20 in any suitable way. Pin 2li may project from a fitting 9 atthe top of the assembly, it being mentioned that these fittings arearranged in two rows, the outer row 22 and the inner row 23 at the endof the assembly having the connection for actuating the blades, outerrow 22 of such fittings being attached to the actuating means andmovable, while the inner row 23 is mounted to be carried by the endframes II and is stationary. The opposite end of the assembly, such asthe bottom of the structure shown in Fig. l, may be provided with asingle stationary row 24 of nttings 9 A spring 25 attached at one end tothe outer end of pin 2|) may be attached at its opposite end to a xedpoint 26, such as to the rod I of the immovable row of fittings 23.Thermostat l5 may comprise any suitable type of thermal device havinganactuating shaft 21 bifurcated at its outer endto -allow a bar 28 toextend through the bifurcation, which bar may be held therein by acotter pin 29. Flexible wire 2| of flexible connection |1 is secured tothe tip of bar 2B. Bar 28 is fulcrumed at 30 to a fixed arm 3| that mayextend outwardly from the housing of the thermostat I5. The connectionpermitting manual operation may be attached at 32 of the lower end ofbar 28. Outer movable row 22 of fittings 9 at the top of the shutterassembly is adapted to be reciprocated by movement of wire 2|.

As shown in Figs. 4 and 5, the end flange 5 of each upper blade section2 is adapted to pivot at 33 about stud 8 carried by the stationary row23 of fittings 9. The movable row 22 of fittings 3 is attached at 34 bymeans of studs 8 to this end flange 5 of each blade so that as thismovable row 22 is actuated, the blade will pivot at 33 about stud 8.Fig. 4 illustrates the blades in closed position, Fig. 5 illustrates theblades in open position. When the temperature of the cooling medium inthe core of radiator I4 rises during the operation of the motor and i-tis desirable to allow the air to pass through the core in order to keepthe temperature from becoming excessive, thermostat I5 is actuated toswing bar 28 and pull wire 2| through its housing I9. v'-,I'his willmei/.erin 29 to the left. as shown Fie. 3,

against the tension of spring 25 and cause the blades to swing to openposition, as shown in Fig. 5. These blades are held in open positionuntil the temperature of the cooling medium drops to a predetermineddegree. I f manual control of the shutter mechanism is desirable, whichmight occur in cold weather when parking the vehicle after the motor hasbeen in operation for some time, the driver may actuate the connectionat 32 so as to cause bar y28 to tilt and release wire 2| so. that it mayreturn to its original position under the action of spring 2 5 vandclose the shutters. Although I have shown a thermally actuated device I5as illustrative of va power means to effect opening and closingadjustments of the blades, it will be understood that the invention isnot necessarily dependent thereupon because the latter may be used andits advantages enjoyed with any other type of power means or with amanual `means alone.

yEach upper blade section 2 is provided with a flange 40 along one ofits vertical edges. Each lower blade section 3 is provided with asimilar flange 4|. The body portion of each of these blade sections 2and 3 may be formed slightly arcuate, as indicated at 42 in Fig. 11.Upper and lower blade sections 2 and 3 are secured together by fasteningmeans 4 so that the convex faceof the vbody portion of lower bladesection 3 seats in the concave face of the body portion of upper bladesection 2. However, side flanges All and 4| are oppositely disposed withrespect to each other. The other vertical edge of each blade section isnot provided with a flange but is adapted to engage against the flanges40 and 4| of adjoining blades when the latter'are moved to closedposition. By referring to Fig. l1, it will be noted that this specificform of the invention has each blade with flange 4I! of each uppersection 2 engaging the opposite free vedge of the upper section of eachadjoining blade, and, in a similar manner, has each flange 4| of thelower section 3 likewise engaging the free edge of the adjoining lowervsection butl in a reverse manner'- with respect to anges 4) of theupper blade sections 2.' In other words, each blade has the flange 40 ofthe upper section 2 substantially continuous with the free edge of thelower section 3. Accordingly, each blade has flange 4| of the lowersection 3 coextensive with the free edge of the upper section 2. l.prefer to expose the concave faces of the blades to the flow of air andplace the convex faces adjacent the core of radiator I4. Hence, the airwill strike the concave faces and be caused to deflect outwardly awayfrom the edges of the blades when in closed position. By referring toFigs.v 11 and 12, opening movement of the blade will cause them to pivotcounterclockwise. This will move flanges 4U of the upper sections 2 awayfrom the overlapping edge of vthe adjoining blades. The flanges 4l oflower sections 3 will move away from the overlapping edges of adjoiningblades. When the blades are in closed position, a tight closure is thusprovided to prevent air from leaking through the shutter mechanism atthe overlapping edges.

Both upper and lower sections 2 and 3 may 'thus be identical, vbeingmerely reversed in positions when they are secured together to form thisupper and lower relation.v 'In -prior art devices of the sectional bladetype, the upper and lower sections are placed together so that flanges40 and 4| are coextensive, this being illustrated in Eig.. 6.' 'Whenpositioned in this manner, an

opening or separation would be provided .equal to the thickness of eachblade between. adjoining blades except where they sections of each bladeoverlap. This. opening. is illustrated at 44. in Fig. 6. By arrangingupper and lower sections 2 and 3 in .the manner shownin Figs. 11 and 12,this openingv or separationis entirely eliminated and a tight closure isthereby. provided. Not only are these openings or. separationseliminated but the upper andlower sections 2 and 3 may be identicalandmade from the same tools as distinguished from aright and left bladeas the resultof -a separate formation of each section necessary inmaking `thel upper and lower sections of the prior art devices.

It is not necessary that each blade be limited to two sections. .Anynumber of sections may be provided. Figs. 9 and 10 illustrate a `bladewith upper section 2 having iiange 40, lower section 3 having ange 4|and an intermediate section having flange 46. In this arrangement,flanges 40 and 4| will be on the same side of upper and lower sections 2and 3, while flange 46 of intermediate section 45 will be on theopposite side. V

Figs. .13 to 23, inclusive, illustrate dierent forms of overlappingflanges and edges of the upper and lower sections of adjoining bladesthat engage each other and eliminatev the separation or opening 44 alongone of the sections of adjoining blades or prior art devices as shown inFig. 6. In Fig. k13, the right-hand blade 41 is provided with iianges 48and 49, along the edges of upper and lower sections 2 and 3 whichoverlappingly engage the edges of theadjoininglefthand blade 53. Upperrsection 2 of blade 41 is provided with a ribV 43 which tends toreinforce the upper section and deflect the wind away from theoverlapping edges whenthe blades are arranged with their convex facesexposed and their concave faces adjacent the core of radiator i4. InFig. 14, right-handblade 41 has a right angularly turned flange 5| onits upper section 2 overlappingly engaging in a trough-like flange 52 onupper section 2 of left-hand blade 50, while the lower section 3 ofleft-hand blade 50 has a, right angularlyv turned iiange 53overlappingly engaging in a trough-like flange 54 on lower section 3 ofright-hand blade 4T. In Fig. l5, right-hand blade 41 has flanges 55 and56 on its upper and lower sections 2 and 3, respectively, ofsubstantially the same general surface contour as the body of sections 2and 3 of the lefthand blade 5|] so as to overlappingly engage itsadjoining edges. In Fig. 16, upper and lower sections 2 and 3 ofright-hand blade. 4." have flanges 51 and 58 adapted to overlappinglyengage the edges of adjoining blade 50, the ange 53 being longer thanflange 51 and having a bead 59 formed thereon to lie in and close thespace between the edge of lower section 3 of blade 5B and the flange 51of upper section 2 of blade 41 where ,the upper and lower sections ofeach overlap in superposed relation. Fig. 17 illustrates upper and lowersections 2 and 3 of blade .41 with flanges 60 and 6|in overlappingengagement with a liange 62 on upper section 2 of blade 5U and the edgeof lower' section 3Y of said blade 50. Fig. 18 illustrates substantiallythe same arrangement as in Fig. 1'1 but with each of flanges and 6|provided with' outturned eds that interlock with similar outturnedendson the overlapping edges of blade 50, the lower section 3 of blade50 having a turned end or iian'ge 6.3 similar tcv ange 62 on the uppersection 2. In Fig. 19, blade 50 has its upper and lower sections2 and 3provided with similar-flanges 62 and 63, while blade 41 has itsupperandlower sections 2 and 3 provided with flanges 60 and 6| formed atslightly different angles than those in Fig. 18. In Fig. 20, uppersection 2 of blade 41 is provided with a bead 64 and no flange. However,upper section 2 of blade '50 has a flange 65 overlappingly engaging theedge of section 2 of blade 41 just outside of bead 64. 'Ihe lowersection 3 of blade 41 has both a ilange 68 and a bead 61, which flange66 overlappingly engages the edge of lower section 3 of blade 50. Fig.21 illustrates flanges 68 and 69 on sections 2 and 3 of blade 41 adaptedto overlappingly engage the edges of adjoining blade 50. Flange 69 islonger than flange 68 and has its edge turned to embrace the edge offlange 68. Fig. 22 is substantially the same as Fig. 16. And Fig. 23shows approximately the same arrangement but upper section 2 of blade 50has a flange 10'engaging the edge of upper section 2 of blade 41.

AS previously explained, upper and lower sections 2 and 3 are formedpreferably by the same tools, and consequently, their arcuate bodies 42will have their inner and outer arcs of the same radii. As a result,outer face 1|- on each section will be formed of a greater arc thaninner face 12. When sections 2 and 3 are placed together in superposedrelation, as shown in Fig. 24, face 1| 'of lower section 3 will not seatupon face 12 of upper section 2. However, fastening members 4 will holdthese sections together, as shown in Fig. 25, under slight tension whenthey are forced together. Thus, 4the sections of each blade will be heldsuperposed upon each other under tension and any tendency of the same torattle while in use will be overcome.

In order to prevent adjoining blades from rattling when they are inclosed position, sections 2 and 3 of each blade may be formed slightlysprung or warped at their lower ends adjacent or along the edges notprovided with iianges 40 and 4|. The warping is of such a character thatthe flanges 40 and 4| will start their overlapping engagement with theedges of adjoining blades substantially at the lower ends of eachsection. Continuedv pivotal movement of the blades to closed positionwill cause the blades to be held closed under tension whereby toovercome rattling caused normally by vibration.

Figs. 27 and 28 illustrate a further variant embodiment of this featureof the invention. Instead of imparting the tension under which theblades are held in closed position by warping the blade sections `as inFig. 26, upper and lower sections 2 and 3 may have-their flanges 4|) and4| slightly tapered in width from top to bottom and be provided withiiange-like troughs 16 and 11 along their opposite edges to receivethese flanges 46 and 4| of adjoining blades. Hence, with flanges 40 and4| slightly larger in Width at the bottom,l they will be engaged firstat the bottom by troughs 16 and 11 as the blades are closed, the resultbeing that the bladespare slightly sprung or warped as they are closedand are thus held underv tension to eliminate rattling by vibration.

As previously mentioned, frame members may be provided along the sidesof the shutter assembly to'provide a supportv for the ends of rods I0.-Each framefmember may be formed of extensibly related upper andlowersections 82 and 83, respectively.` To provide a tight closurebeitween thesesotions of frame members I I andthe end blades, thesections may be provided with iront Hang-'es I8 and side' walls I9 andinwardly formed slotted ,sides I2. Side walls 'I9 of the right-handtraine sections may be wider than side wall 1.9 oi the left-hand framese'otions, if their adjacent blades Aare arranged to have the adjoiningedge o'i flange close'against thevinside face of their flanges 18, suchas would be the case if the blades are arranged to pivotcountere'loekwise te open positium.A The flange and edge of the bladesections adjacent side wall 'I9 of the' left-hand frame members willclose against the outside face of aange 18.

If perforatiens 4 are provided in the made sections er the variantembodiments shown herein at the time the latter are made and remainopen, there will be a considerable leakage of air through theseapertures, which is undesirable and obviously reduces the eiliciency ofthe shutter mechanism. It has been Suggested to cut the material partway to form knock-outs which can be removed at the time the shutters areassembled, thereby providing the apertures that are only necessary tosecure the desired extensible adjustment of the sections. In the presentconstruction where assembly of the shutter may be required in a smallspace permitting restricted vision by the workman, as where the shuttermay be assembled upon a radiator front having a false grille, the use ofpunches to remove the knock-outs adds to the labor necessary to completethe assembly. I find that the assembly may be greatly facilitated inthis respect by punching out the perforations 4 at the time the shuttersections are made and to use a lacquer or paint Bil for the shuttersections that will be sufficiently viscous to form a webbing 8| thatwill dry and keep the apertures 4 closed, as shown in detail in Fig. 29,until lips 4 of opposite sections are pushed thereinto during assemblyof these sections. Hence, a punch to remove the knock-outs will noAlonger be necessary and a considerable saving in labor and time duringassembly affected in a device of this type.

The foregoing description is believed to disclose fully a shuttermechanism of new and novel characteristics and capable of accomplishingresults of great value and importance in the art. Certain advantageousfeatures in construction of the sectional parts that may be assembled tothe radiator front to form a built-up structure within limited spacebetween the grille work and the radiator will be apparent to thoseskilled in the art. The general streamline design of the body with thegrille work forming a part of the design is not affected. Moreover, theconstruction advantageously permits easy insertion of the mechanismbetween the grille work and the radiator front and assembly thereof withminimum labor, eiort and expense. It will be understood, of course, thatthe shutter construction need not be actually built up upon the radiatorfront. The construction may be rst assembled and then mounted upon andattached to the radiator core, such as might be desirable where thegrille work does not interfere with the insertion of an assembledstructure, or in cases of tractors or stationary engines not employing afalse front for their radiators. Such form of assembly was likewisecontemplated in connection with the struc-ture shown in my prior patent.

Without further elaboration, the foregoing will so fully explain thegist of my invention that others may, by applying current knowledge,

-disposed with respect to each other and to the ii'anges' on adjacentsections of adjoining blades.

2'. In a shutter blade assembly',l a plurality of piv'otally-I mountedshutter blades adapted to overlap each other when in closed position,each blade comprising at least two sections arrangedv one upon the otherin extensible relation, and flange means' for eiiecting an airtightoverlapping engagement between the overlap of both sections of eachblade with both sections of adjoining' blades.

3. In a shutter blade assembly, a plurality of pivotally mounted shutterblades having adjoining portions overlapping each other when the bladesare in closed position, each blade comprising at least two sectionsarranged in eX- tensible relation, and a longitudinal edge on eachsection, the flanges of adjacent sections of each blade being disposedalong opposite longitudinal edges of said adjacent sections, said angeshaving a substantially air tight overlapping engagement with theoverlapping portion of adjacent sections of adjoining blades.

4. In a shutter blade assembly, a plurality of pivotally mounted shutterblades having portions overlapping each other when the blades are inclosed position, each blade comprising at least two sections arrangedone upon the other in extensible relation, the sections of each bladeand their said overlapping portions engaging in airtight engagement theoverlapping portions of the adjacent sections of the adjoining bladeswhen said blades are in closed position.

5. In a shutter blade assembly, a plurality of shutter blades, means formounting said blades so that adjoining blades swing to close upon eachother in overlapping relation, there being overlapping portions alongthe adjoining edges of said blades, each blade comprising at least twosections arranged one upon the other in extensible relation, said bladesections each having the overlapping portion along one of its edges inthe form of a flange, the iianges of the sections of each blade beingadapted to engage along opposite surfaces of the adjoining sections ofadjoining blades when said blades are swung to close upon each other.

6. In a shutter blade assembly, a plurality of pivotally mounted shutterblades having adjoining portions overlapping each other when the bladesare in closed position, each blade comprising at least two sectionsarranged one upon the other in extensible relation, there being at leasttwo rows of said sections, and iianges forming the overlapping portionsalong one edge of each of said sections, said flanges of the sections ofone row being disposed along the corresponding edges but along oppositeedges with respect to the second row whereby to overlap adjoiningsections of each row on the side remote from the other row.

shutter blades, means for mounting said blades so that the oppositeedges of each blade swing in a direction to engage adjoining .blades onopposite sides, each blade comprising at least two sections arranged oneupon the other, and an overlapping flange on one edge of each section,said flanges of the adjacent sections of the same blade being oppositelydisposed valong the edges thereof in order to engage the adjoining edgesof adjacent sections of adjoining blades and form a continuous closurepreventing the passage of air between said blades.

8. vIn a shutter blade assembly, a plurality of pivotally mountedshutter blades adapted to engage adjoining blades on opposite sides inoverlapping relation, said blades each comprising at least two sectionsarranged one upon the other, said sections being arranged in rows, andmeans at the edges of said blades for effecting a tight engagement atthe overlap of the adjoining sections of each row whereby to provide acontinuous closure along the sections of each row and between thesections of each blade.

9. In a shutter blade assembly, a plurality of shutter blades, means formounting said blades so that adjoining blades swing to close upon eachother; and overlapping portions between adjacent edges of adjoiningblades, said overlapping portions including cooperating flanges, one ofwhich between adjoining blades is larger at one end than the other endand the other of which is of substantially constant size from end to endwhereby to eiect engagement at said end before said -other end duringsaid closing movement of said blades so as to place said blades undertension to prevent the same from rattling while in closed position.

10. In a shutter blade assembly, a plurality of shutter blades, eachblade comprising at least two sections arranged in extensible relation,means for holding said sections of each blade in extensible relation,said means comprising projections on one section and a plurality ofapertures on the other section of each blade, and a dried nishingcoating on said blades, saidcoating closing said apertures in the formof a puncturable webbing, whereby theA unused apertures remain coveredby said coating.

EDWARD A. BLUMENTHAL.

